Storage drums of the type to which this invention pertains are commonly employed by industry because they are relatively easy to clean and are normally reusable. In general the drums have a semi-cylindrical bead rim about their upper ends and the lids have a mating peripheral lip which fits over the drum bead and an intervening gasket seal. An annular split metal closure ring is posed over the lid's lip and drum bead and then compressed to bring the ends of the ring in near abutting relation to secure the lid in place and compress the gasket. This effects a seal between the drum and lid. Typically, a pair of locking lugs or clamp members are welded to the ring one on either side of the split therein so that they extend outwardly of the ring. The mounted lugs or clamps have coaxially aligned openings for passage of a tie bolt therethrough. In some instances a nut is associated with one of the lugs to engage the outer threaded end of the tie bolt and in other instances the opening in that lug is internally threaded to engage the bolt threads. In either instance preferably the opening in the other lug is unthreaded for free passage of the tie bolt. Appropriate threading movement of the bolt serves to tighten the bolt connection between the lugs and accordingly compress the ring to effect sealed connection between the lid and drum.
One of the major problems encountered with such described assembly is that all too frequently the tie bolt tends to back off or loosen during transportation and handling of the drum which leads to undesirable loosening of the ring and disruption of the sealed relation between lid and drum.
The present invention is addressed to means for alleviating this problem.